Position locator



Feb. 18, 1947. L. w. CHUBB. 2,416,155

POSITION LOCATOR Filed March 27, 1943 s Sheets-Sheet 1 Ric/7L far 22 Zefz far Rig/7a far 2/ left Ear Q 1 6 1 36 as 37 i WITNESSES:

g T B- INVENTOR Lew/s W C/Mb.

ATTORNEY Feb. 18, 1947. w CHUBB 2,416,155

POSITION LOCATOR L eff far liiy/nf far W & 5':fiece/ver Race/var Hemp/lone JINVENTOR+ ATTORNEY Feb. 18, 1947. L. w. CHUBB 2,416,155

POSITION LOGATOR Filed March 27, 1943 5 Sheets-Sheet 3 1%; 4a. @477 )WM mm; M/ 074mb.

ATTORNE Y WITNESSES: lNVENTOR Feb. 18, w C UB POSITION LOCATOR Filed March 27, 1943 5 Sheets-Sheet 4 INVENTOR Lew/Is I IZ C/wbb.

BY A

ATTORNEY 1947. w, CHUBBI 2,416,155

POSITION LOCATOR Feb.

Filed March 27,' 1943 s Sheets-Sheet 5 Receiver Transmitting 05 c /'//a L a r.

Laud Speaker INVENTOR f7;- 9 Left W15 m 0741M.

ATTORNEY Patented Feb. 18, 1947 UNITED STATES PATENT OFFICE POSITION LOCATOR Lewis W. Chubb, Pittsburgh 21, Pat, assignor to Vi'estinghouse Electric Corporation, East Pittsburgh, Pa, in corporation of Pennsylvania Application March 27, 1943, SerialNo. 480,777

14 Claims. (011250 15 This invention relates to position locating appara-tus and more particularly to such apparatus adapted for use in determining the position of objects moving relative to a locating station, such as ships, airplanes, tanks, etc. It has for one of its objects to provide improved apparatus for deter mining the position of objects.

Another object is to provide improved apparatus whereby waves directed from a wave generator or transmitter and subsequently reflected from the object to be located back to a receiver or detector may be utilized to accurately determine the position of the object.

A further object is to provide improved apparatus whereby the relative movement between a stationary receiving station and a moving object is utilized in connection with radiated and reflected waves to accurately determine the position of the moving object. u A still further object is to provide improved apparatus which-permits of the use of the bin= aural sense of the operator in connection with radiated and reflected alternating waves to accurately determine the position of distant objects.

A still further object is to provide improved apparatus for accuratelylocating a distant object whereby waves radiated from a wave transmitter are mixed with Waves reflected from the distant object; and the subsequent beat note utilized to accurately determine the position ofthe object. V

A still further object is to provide improved ap paratus having an antenna system which may be utilized in one position for approximately locating a distant object, and may be moved to another position, in which position it is utilized to determine more nearly the exact position of the object.

These and other objects will be apparent from the following description taken in conjunction with the accompanying drawings wherein:

Fig. 1 is aview partly in perspective and partly schematic, illustrating one embodiment of the invention, whereby sonic or supersonic waves are 2 Fig. 5 is a side perspective view of an improved antenna system for use with high f-requencyapparatus for determining the position of objects the antenna system being positioned for approximate location of distant objects; 7

Fig.6 is a partial perspective View of the apparatus shown in Fig.- 5, with the antenna system positioned for more accurate location of distant objects; i Fig. 7 is a diagrammatic View illustrating an a rangement wherein the antenna system shown in Figs. 5 and dis utilized; v a u 1 Fig. 8 illustrates the pattern of the polar beam of each of the reflectors shown in Fig.3. This figure also illustrates the patternof the polar beam of the antenna system; shown in Figs.- 5, d and 7, when the system is in the position indicated Fig. 9 illustrates the polar beam of the antenna system, shown in Figs. 5, 6 and 7, when the system is in the positionindicated in Fig. 6; and

Fig. 1-0 is a perspective view of an alternate form of reflector that may be used withthe antenna system illustrated in Figs. 5, 6 and "7.

Referring to the drawings,- Figs. land. 2 illustrate generally one embodiment of this invention wherein continuous sonic or supersonic waves are utilized to locate a, distant moving 6b-. ject, such-as an airplane, tank, ship er the like. To locate a distant moving object with this apparatus, the area which is believed to include the object sought is scanned with a highly directive beam of sonic or supersonic waves. These waves, upon. striking the object, are scattered and refiected back to aplurality of detectors or receivers located near the source of direct waves. The reflectedwaves are combined with a portion of the direct waves and the beat frequency producd by this combination is utilized to excite the binaural sense of an operator to accurately locate the position of the object in azimuth and elevation. The apparatus illustrated in Fig. 1 includes a directive antenna system com-prising an array of two wave gathering or receiving parabolic reflectors l0 and II spaced apart in azimuth on a supporting member i2 and two wave gathering dif receiving parabolic reflectors l3 and IA spaced apart in elevation on a, separate supporting member I5 for receiving the reflected waves, and a transmitting parabolic reflector [8. The receiving reflectors are all located in the same planeai'id disposed equal distance and equal angularly about a center-line perpendicular to the plane. fl'he transmitting parabolic reflector I8 is disposed on this center line forwardly of same plane. A

. through similar conductors and ceivers.

derstood that although parabolicreflectorshave been shown for transmitting the direct waves and 'i for receiving the reflected wavesjany suitable horn, reflector, or other directivedevicemay be used without changing the scope of the invention.

The transmitting reflector I8 may be of any suitable size; hOWEVELlt has been found that a reflector of about 30 centimeters in diameter gives very good results. Continuous sound waves are produced at approximately the focal point of thereflector I8 by an air-jet sound-wave generator 25. This generator is supplied with air through a tube 26 connected to an air reservoir 21-which is kept under substantially constant pressure by an air compressor 28 and a pressure regulating valve 29. Some suitable means, such as a valve 24, may be provided for controlling the wave generator 25. This generator produces a carrier frequency of approximately 10,000 cycles per second. and withthis specific frequency and a reflector 30 centimeters in diameter, it has been foundthat the diagram of the polar beam of the reflector I8 is fairly narrow, approximately 5 degrees. This narrow beam insures very accurate location of the object sought.

For determining the distance from. the locating station to the moving object it may be desirable to "pulse the transmitter output and to measure the time required for a pulse to reach the moving object and return. Pulsing of the airjet sound-wave generator conveniently may be effected by intermittently dropping the pressure of the air supplied thereto.-

' In Fig. 1, an air outlet 24a is provided between the valve 24 and the wave generator 25. This outlet normally is closed by a valve 24b which is biased into its closed position by means of a spring 240. The valve is operated by a suitable cam mechanism which may take the form of an eccentric pin 24d mounted on a shaft that is rotated by an electric motor Me. The eccentric pin is connected to the valve 241) by means of a link 24f.

When the valve 24b is opened the pressure of the air supplied to the wave generator 25 drops sufliciently to interrupt the production of waves thereby. Consequently, when the motor 24 is energized to rotate the eccentric 24d at a suitable rate, waves are transmitted from the wave generator 25 in pulses. The time required for a pulse to travel to the moving object and return to the locating station is a function of the dis tance therebetween.

The receiving reflectors II]; II, I3 and I4 are allidentical and'are approximately the same size asthetransmitting reflector I8. A suitable detecting device, such as a microphone 32, is located at approximately the focus of each of the receiving reflectors for detecting the reflected waves; Y I '1 The microphone in the azimuth-locating reflector'lfl'is connected through conducto s 33 and detail in Fig. 2.

34 to a receiver 35, the output of which is connected by conductors 36 and 31 to the headphone for the right ear (Fig. 1) of the set of headphones 2I, and, likewise, the microphone in the azimuthlocating reflector I I is connected through similar conductors and an identical receiver to the headphone for the left ear of the set of headphones 2 I The microphones in the elevation-locating reflectors I3 and I4 are also likewise connected to the headphones for the left and right ears (Fig. 1), respectively, of the set of headphones 22,

identical re- As stated above, all of the receivers indicated in Fig; 1 are'identical, and for the purpose of illustration, only one receiver is illustrated in Each receiver 35 includes a transformer 39, a triode type tube 60 which provides a stage of high frequency amplification, a multiple electrode tube 4|, which serves as a rectifier and also provides a stage of audio-frequency amplification, and another triode-type tube 42, which provides a final stage of audio-frequency amplification. The'receiver is connected to its respective microphone 32 through the conductors 33 and 34 which connect to the primary of the transformer 39. The output from the receiver' is connected to one of the headphones by the conductors 3B and 31.

To locate an object with the apparatus shown in Figs. 1 and 2, the sound-wave generator 25 is set into continuous operation by opening the valve 24, and the transmitting reflector I8 is pointed in the general direction in which itis believed that the object is situated. Most of the sound waves generated by the wave generator 25 are directed outwardly by the reflector I8, along a path indicated by the arrows 44 in Fig. 1, in a narrow beam; however, a small amount of the direct waves passes directly to the receiving reflector. The array of reflectors is then rotated in azimuth and elevation until the object that it is desired to locate is contacted. When the waves 44 contact an object, such as a moving tank 38 (Fig. 1), they are scattered and some of them are reflected by the object, along 'the paths indicated by the arrows 45 (Fig. 1), back to the receiving reflectors. Because the object is moving, the reflected waves 45 will be of different frequency'than the waves that are transmitted directly to the receiving reflectors, the difference in frequency being proportional to the component of velocity parallel to the transmitted waves represented by the arrows 44.

The reflected and direct waves picked up by the microphones 32 and fed to the receivers 35. In the receivers, they are amplified by the tube 40, then they are detected to produce beats of audible frequency, and further amplified by the tube ll. The beat notes are further amplified by the tube 42 and fed to the two sets of headphones 2I and 22 to excite thebinaural sense of the operators. A v I I 1f the transmitting reflector I8 points directly at the tank 38, the receiving reflectors I 0 and H will be equal distances from the tank and the reflected waves picked up by the reflectors I0 and I I will be in phase. This causes the beat notes fed to the' respective headphones of the set of headphones 2| to .be in phase an of 'equal magnitude; In this'instance, the signal appears to remain stationary inthe center of theoperr: ators head, which indicates to the operator that the reflector I8 is pointing directlyat the tank;

If the transmitting reflector I8 is shifted, from pointing directly at: the tank, so that it points slightly to the left of the direction of the tank, the receiving reflector l will be closer to the tank than the receiving reflector H and the reflected wave picked. up by the reflector Ill will be slightly'advanced in phase and the reflected wave picked up by the reflector H will be retarded in phase by an equal amount. The amount of phase shiftis proportional to the difference in the echo paths from the tank 38 to the reflectors Ill and l i. In this instance, the signal appears to move from the center of the head of the operator wearing the azimuth headphones towards his right ear. Accordingly, if the transmitting reflector I8 is shifted, from pointing directly at the tank, so that it points slightly to the right of the direction of the tank, the receiving reflector II will be closer to the tank than the receiving reflector Ill, and the reflected wave picked; up by the reflector "ll will be slightly advanced in phase and the reflected wave picked up by the reflector It! will be slightly retarded in phase. In this instance, the signal appears to move from the center of the operator's head towards his left ear.

To accurately focus the system on a distant object, the azimuth operator merely rotates the array of reflectors in azimuth until a signal is received in the headphones 2|, then he manipulates the reflectors to the right or left until the signal appears to remain stationary in the center of his head.

' To accurately locate an object in elevation, the elevation operator manipulates the array of reflectors in elevation" in a like manner until the signal received in the headphones 22 appears to remain stationary in the center of his head.

There will be a phase shift of one complete cycle of the beat note in the headphones for each half carrier wavelength of motion. of the receiving reflectors. With supersonic waves of 10,000 cycles having a wavelength of around 3 centimeters, the frequency of the. beat note will be in a good range to be heard when the approach or retreat of an object, such as a tank, is above It is understood that reflections from stationary objects, such as trees, hills, buildings, and the like, will not give a signal since the reflected waves will be of the same frequency as the direct waves that are transmitted directly to the receiving reflectors, and,,consequently, no heat note will be created to excite the blnaural sense of the operators. 7

Figs. 3 and 4 of the drawings illustrate a second embodiment of this invention wherein cons tinuous radio waves are utilized to accurately 1ocate a moving distant object. This embodiment contemplates scanning the area which is believed to include the object with a highly directional beam. of continuous radio waves. The waves, upon striking the object sought, are reflected back to a plurality of detectors or receivers near the source of direct waves. The reflected waves are then gathered and utilized toexcite the binaural sense of the operator to accurately locate the position of the object sought.

The apparatus of this embodiment includes an antenna system comprising a parabolic transmit ting reflector 50 and a pair of parabolic receiving ordetecting reflectors 5! and 52 located at equal distances on opposite sides of the reflector 5B. The transmitting reflector may be advanced in position relative to the receiving reflectors. The reflectors 50, 5| and 52 are all rigidly attached to a member 54 which is adapted to be rotated in azimuth about apoint The transmitting reflector 50 is supplied with continuous radio waves from a transmitter 51'. This transmitter may be of any suitable design, but it is preferred to use atransmitter which is designed to generate short radio waves having a wave length, for example, of approximately 3 centimeters. For the purpose of illustration only, a transmitting oscillator of the "reflex klystron type has. been illustrated; however, an oscil lator of the magnetron type will also serve the purpose. Both of these types of oscillators are well known in the art, and it is not believed necessary to describe the same in detail.

The transmitter 51 is located behind the transmitting reflector 5i! and the waves from the transmitter are conducted to the reflector 50 through a coaxial cable 58 and a wave guide 59. The transmitting reflector 50 has a diameter of many times the wave lengths at which. the ap-' paratus operates. In this way, a highly directional beam of radio waves is produced. A small disc reflector 60 placed directly in. front of the wave guide 59 causes substantially all of the transmitted waves to be reflected outwardly"from the reflector 60.

The receiving reflectors 5| and 52 also have a diameter of many times the wave length at which the apparatus operates, and are preferably approximately of the same diameter as the transmitting reflector 5|]. A small disc reflector BI is also located near the focus of each of the receiving reflectors 5| and 52.

A low power local oscillator 63 of the reflex klystron or magnetron type is located behind each of the receiving reflectors 5i and 52. The output from each of these oscillators is connected to its respective receiving reflector b a coaxial cable 64 and a Wave guide 65. The small disc reflectors 6! cause substantially all of the reflected waves that return to the receiving reflectors to be directed into the wave guides 65. The frequency supplied by the local oscillators 53 is mixed with a portion of the direct wave and the reflected waves in the wave guides 65. It is understood that a suitable tie-iii circuit may be provided-to keep the two oscillators 6 3 in step.

A crystal detector 6! is positioned in each'of the wave guides 65 to produce the beats resulting from the mixing'of the direct waves, the reflected waves, and the Waves supplied by the local oscillators 53. Each crystal is connected through a coaxial cable 58 to a receiver 59. The output from each receiver 69 is, in turn, connected, respectively, to one of a set of headphones 10 which are worn by the operator.

Both of the receivers 69 are identical, and for the purpose of illustration, only one receiver is illustrated in detail in Fig. 4-. Each receiver includes a transformer i5, a local oscillator ll, a mixing tube 12, an intermediate-frequency am} plifying tube 13, and a detector and audio-ire quency amplifying tube 14." A suitable tie in circult may also be providedfor keeping the two 'o's cillatorsll'in step. i

To locate an object with this apparatus, the transmitting oscillator is set into operation to generate continuous radio Waves. Some of these waves are directed directly into the reflectors 5i and 52; howeven'most of them -are directed outwardly by the reflector 5G in a narrow'beain, along the path indicated by the err'owslt' Fig. 3). These waves, upon strikingan object, such as a tank 38 (Fig.3), are scattered and reflected back, along the paths indicated by the arrows TI,

to the receiving reflectors and 52. The reflected waves, along with the small amount of direct waves received directly from the transmitting reflector 50, are directed into the respective wave guides 55 by the disc reflectors 6|. These direct and reflected waves are then mixed in the respective wave guides 65 with the oscillations supplied by the respective local oscillators 63.

The combination of waves in each wave guide 65 is detected by its respective crystal detector .61 to produce an intermediate frequency which is conducted through the respective coaxial cable 58 tothe respective receiver 69. In the receiver 69, these intermediate frequencies are further mixed in the respective tubes 12 with the oscillations supplied by the respective local oscillators II to produce another set of lower intermediate frequencies. These lower intermediate frequencies are further amplified in the respective tubes 13, and then they are detected to produce an audio beat and further amplified in the respective tubes M. The output from each of the tubes 14 is connected to one of the headphones of the set of headphones 10.

If the transmitting reflector 50 points directly at the tank 38 (Fig. 3), the receiving reflectors 5| and 52 will be equal distances from the tank and the reflected waves picked up by the reflectors 5| and 52 will be in phase. This causes the beat notes fed to the respective headphones '10 to be in phase and of equal magnitude. ,In this instance, the signal appears to remain stationary in the center of the operator's head, which indicates to the operator that the reflector is pointing directly at the tank.

If the transmitting reflector 50 is shifted, from pointing directly at the tank, so that it points slightly to the left of the direction of the tank, the receiving reflector 52 will be closer to the tank than the receiving reflector 5|, and the reflected wave picked up by the reflector 52 will be slightly advanced in phase and the reflected wave picked up by the reflector 5| will be retarded in phase by an equal amount. The amount of phase shift is proportional to the difference in the echo paths from the tank 38 to the reflectors 5| and 52. In this instance, the signal appears to move from the center of the head of the operator to his right ear. Accordingly, if the transmitting reflector 5|! is shifted from pointing directly at the tank, so that it points slightly to the right of the tank, the receiving reflector 5| will be closer to the tank than the receiving reflector 52, and the reflected wave picked up by the reflector 5| will be slightly advanced in phase and the re-' flected wave picked up by the reflector 52 will be slightly retarded in phase. In this instance, the signal appears to move from the center of the operators head to his left ear.

To accurately focus the system on a distant object, the operator merely rotates the array of reflectors until a signal is received in the headphones 10. Then he manipulates the reflectors to the right or left until the signal remains station ary in the center of his head. Which indicates to him that the transmitting reflector 5B is pointing directly at the object. 1 1 Although separate local oscillators 63 have been shown for each of the receiving reflectors 5| and 52, it is understood that a single oscillator may be used to supply both of the reflector with-a frequencyto heterodyne the received waves. It has been found that good results can'be obtained by using a transmitter frequencyof 10.090 inegac'yclesand beating thereflected wave withva frequency of 9,970 megacycles, which frequency is supplied by the local oscillator 63, and then beating the resultant beat frequency of 30 megacycles with a second frequency of 29.535 megacycles, which is supplied by the receiver oscillators I This gives a final beat point of approximately 465 kilocycles. This frequency is easy to amplify.

In some instances, both of the local oscillators 63 may be omitted. The reflected wave and the directly received wave will then be detected by crystal detectors 6! to produce an audible frequency directly which may then be amplified by conventional audio amplifiers and applied to headphones.

In some instances, for example, for the sake of economy, a single oscillator may be substituted for the two receiver oscillators II. It is also understood that in some instances the receiver oscillators may be omitted. The mixture of the direct waves, reflected waves, and oscillations supplied by the local oscillators 63 is then detected to produce an audible signal. This signal is then amplified and applied directly to the headphones I0. I

For example, the system of Fig. 3 may be modified in the manner shown in Fig, 4a. Referring to Fig. 4a it will be observed that the system therein illustrated differs from the system of Fig. 3 only in the provision of a single high-frequency oscillator 63 and a single low-frequency oscillator 7| for modifying the signals received from both of the reflectors 5| and 52. The output of the high-frequency oscillator 63 is conducted through two wave guides 65' to the two crystal detectors. These wave guides 65' are adjusted to provide outputs from the oscillator which are in phase at the crystal detectors. The receivers 69' of Fig. 4a are similar to the receivers 69 except for the provision of the single oscillator H which delivers in-phase oscillations to the two mixing tubes .12.

Although this embodiment has been described for location in azimuth only, it is understood that it may be adapted for locating in elevation also.

Fig. 8 illustrates the polar beam for the transmittingreflector 50, it being understood that the polar beam of each of the receiving reflectors is substantially this same pattern. It is known that the polar beam of a 30 inch reflector transmitting a 3 centimeter wave is 3 or 4 degrees wide at half energy. When the reflector 50 is pointed, along the line 19, directly at an object, such as indicated by the dotv 8|] (Fig. 8), the receivers 69 will get a maximumsignal and the binaural sense will indicate that the reflector 5|] is pointed directly at the object 80. However, it is appreciated that, due to the width of the polar beam, when the member 54 is rotated so as to advance the receiving reflector 5| one-half transmitter wave length and retract the receiving reflector 52 onehalf wavelength, or vice versa, there will be another maximum signal and the binaural sense will indicate that the reflector 50 is pointing di rectly at the object, thus giving an ambiguous signal on each side of the proper position. Ac:- cordingly, the receivers will also respond to a plurality of objects, such as indicated by the dots 8|] and 8| (Fig. 8), which may fall within this wide polar beam, and the position of .the object indicated bythe binaural sense will. not be a true position of either of the-objects but will bea compromise position. This conditionis objectionable where-it-is desired to veryaccurately locate an p -io un l i r 9 Figs. 5, 6 and '1' of the drawings illustrate an arrangement embodying an improved directive antenna system, where in the polar beams of both the transmitting and receiving reflectors are greatly sharpened or narrowed in at least one direction, so that when a receiver indicates a maximum signal, the transmitting parabola is focused directly on the object, thereby eliminating the ambiguous maximum signals that are obtained with a wide polar beam and also eliminating the compromise positions obtained from a plurality of objects, However, the polar beam of this system is fairly wide in one direction, which p r.- mits quick approximate location of objects. Modifications of this antenna system may be with either high-frequency sound-Wave systems or high-frequency radio-wave systems.

The antenna system includes a row of transmitting reflectors T and a parallel row of receiving reflectors R mounted on a frame 85, which is connected by means of 'a U-shaped member 86 to another member 81, which, in turn, is connected to arms 88 and 89. The arms 88 and 89 are in turn attached to a standard 80, which may be rotated through 360 degrees about a base member 1 9|. The U-shaped member 86 is pivoted to the member 81 at 92, which permits the frame 85, carrying the transmitting and receiving reflectors, to be rotated at least 180 about the pivot '92. The member 81 is pivoted to the arms 88 and 3 89, at 94 and 95, respectively. The pivots 94 and 95 permit the transmitting and receiving reflectors to be rotated at least 180 in elevation to focus the system in elevation.

It is intended that this antenna system be used in the position indicated in Fig, 5 to approximately locate in azimuth the object sought. When the antenna system is" in this position, the resulting polar beam in azimuth of all of the transmitting reflectors is approximately the same "width a the polar beam for a single transmitting reflector the same size as a sin le reflector T, it being understood that the resulting polar beam of all of the receiving reflectors is substantially the same pattern. If the reflectors T are --the same size as the reflector (Fig. 3),

this polar beam will bethe same as the diagram illustrated in Fig. 8. Thi beam is fairly Wide, and it Will be appreciated that the receiver will respond'to multiple targets or objects, such as indicated by the dots 80 and '81 (Fig. 8), when two or more objects 80 and 8| are within the solid angle of the polar beam. However, such a compromise position is sufficient togive a quick approximate location of the object sought.

After the object has been approximately located as described above and it is desired to acourately locate the same for sighting agun or the like, the antenna system is rotated aboutthe pivot 92 to the position shown in Fig. 6. In this position of the system, its polar beam is sharpened considerably in azimuth, a indicated by Fig. 9. This polar beam can be made approximately 22 or less at half ener y, which is approximately twice as sharp asthe beam illustrated in Fig. 8. This sharp polar beam permits focusing the systemaccurately on a single object, such asihdicated by the dot 80, and near objects, such as indicated by the dot 8|, will give little or no indication or signal.

tinctadvantage to locate} anobject in azimuth if its approximate elevation is known. For example, in order to easily locate an airplane near the horizon, the antenna. system is positioned as indicated in Fig. 5. Then the system is rotated in azimuth about the base 9| until a signal is picked up. After the airplane has been approximately located in thi manner, the antenna system is rotated about the pivot 82 to the position indicated in Fig. 6, and manipulated in azimuth about the base 2! until a miximum signal isobtained. This maximum signal indicates the accurate azijmum of the airplane.

With a finite number of pairs of parabolas,

there will be several maximum signals. The first and greatest maximum will be when the phase of all of the reflected waves is the same. This condition exists when frame (Fig. 6) is normal to the reflected waves. The next major maximum will be when the rows of reflectors have been rotated through an angle such that there is one wavelength difference in the paths of the reflected waves received by the pair of reflectors having the shortest radius from the pivot 82. These multiple maxir'na would ordinarily give some ambiguity to the results; however, such ambiguity will be eliminated because successive maxima to the side of the central maximum will be of diminishing amplitude because of the sharp directional e'fiec't of both the transmitting and receiving paraboloids, giving a diminished res'ponse when turned to the side.

It will be appreciated that the signal ied from an oscillator to the various transmitting paraboloids preferably should be of equal energy and of the same phase. This can be realized by using a wave guide system such as described hereinafte'r. In the receiving system, the various component signals from each receiving parabola must be summed vect'orially before detection and each receiving parabolashould feed a signal of equal amplitude to the wave guide system. The total signal then passing out through the final wave guide to the detector should be the vector sum of the various component waves picked up by the separate receiving paraboloids. This is accomplished as illustrated in Fig. 7

This figure is diagrammatic only. However, when considering the same, it is assumed that the point 92' corresponds to the pivot 92 shown in Figs. 5 and 6. It is seen from this figure that the transmitting reflectors of equal radius from the point 92 are connected together .by means of wave guides 98 arr-d991, which are fed from wav'e guides Hi8, which are in turn red from a, main wave guide or'fee ipellll, which connects to a transmitting oscillator I816. The arrangement of wave guides from the feed pipe [Ill to eachof the reflectors T is such that their' impedances are matchedand that their optical lengths are equal or differby an integral number of wavelengths. Such an arrangement will feed an equal amount of energ to each reflector T, and they win an transmit in the same phase. correspondingly, all of the pairs of receiving reflectors R" of equal radius from the point92 are connected together by wave guides 182' and H13, which converge into wave guides i84,allof whichconverge into a main wave guide 1-115 for connecting the system to crystal detector H11. The arrangement of the wave guides from each of the reflectors R to the ma n wave guide I85 is also s'u ch that their impedances are matched and that their optical lengthsare equal or, differ by an integral number P wa e en s, This w reguessesan? up ,v'ectorially' thecarrier frequency from all of arteries the different pairs of reflectors before detection. The detector I! is connected to a receiver I 08. This receiver may be of the type shown in Figs. 31 and 4, or any other suitable type. The output "from the receiver I08 is connected to an indicator I 09 which shows the magnitude of the signal created by the reflected waves. The indicator I09 may be a speaker or head set by which the operator can distinguish the intensity of the audio signal, or it may be a cathode ray oscilloscope which will visually show the amplitude of the signal received.

' By adjusting the radius and number of the various transmitting and receiving reflectors, almost any degree of sharpness of the polar beam can be obtained in one direction.

Although a plurality of parabolic reflectors have been shown and described for directing the transmitted waves and gathering the reflected waves, it is understood that a single reflector may be used for directing or gathering the waves without changing the scope of this invention. Fig.

'10 illustrates a single reflector that may be substituted for each of the rows of reflectors shown "in Figs. and 6. This reflector is formed by cutting a central section from a large parabolic reflector. When this reflector is in vertical position, as indicated in Fig. 10, its polar beam is Qwidein azimuth, such as the beam illustrated in Fig. 8, but, after it is rotated through 90 or to horizontal position, its polar beam is narrow in azimuth, such as the'beam illustrated in Fig. 9.

An important advantage of this antenna system is that when the system is in the position indicated in Fig. 5, the wide polar beam permits the object sought to be quickly approximately located in azimuth, and then after the object has been approximately located, the antenna system may be rotated about the point 92 to the position indicated in Fig. 6, in which position the object may be accurately located.

With the arrangement just described, it is the maximum signal that indicates when the transmitting reflectors are pointed directly at the object. However, it is understood that the binaural sense of the operator may be utilized to determine the position of the object. This may be accomplished by connecting all of the receiving reflectors on one side of the pivot 92 to one main wave guide and connecting all of the receiving ireflectors on the opposite side to another main "wave guide, then connecting the two main wave guides, through suitable receivers and headphones, to the two ears of an operator in the grnainner discussed for Figs. 3 and 4.

p The apparatus described hereinbefore provides means for very accurately locating a distant moving object in azimuth, which permits of very ac curate laying of guns, such as anti-tank guns and anti-aircraft guns which have a very flat trajectory, wherein the distance to the object does not have to be taken into consideration in laying the guns. However, if it is desired to also determine the distance from the locating apparatus to the object, a simple means for making such measurements may be provided by pulsing the wave generator or transmitter after the transmitting reflector has been accurately directed at the object and measuring the time that elapses between the projection of a pulse of direct waves and the reception of the reflected wave, by means known to those skilled in the art.

A simple and convenient means for indicating the direction of the object or its location in azi- "muth with respect to the position'of the appa- 12 ratus is illustrated in Fig 5 by the scale 96 and pointer 91. It is understood that this arrangement is also applicable to the apparatus shown in Figs. 1 and 3. A similar scale 96A and pointer 91A are illustrated for indicating the position of the object in elevation. However, it is understood that any other suitable means may be substituted for the scales and pointers illustrated without changing the scope of this invention.

From the foregoing description, taken in connection with the drawings, it is seen that this invention provides improved apparatus for accurately locating the position of moving objects. This invention is especially useful for locating moving objects, wherein the object is not visible to the eye, such as the location of tanks, airplanes, ships or the like, at night, in smoke screens or fogs. This is permissible because of the fact that the sound waves and radio Waves utilized will readily penetrate darkness, smoke screens, fog, and the like. It is also seen that, by utilizing the frequency of the received echo waves for heterodyning with the direct wave to produce a beat for exciting the binaural sense of the operator, a moving object may be readily distinguished from stationary objects, and its direction accurately determined. In effect, the frequency of the signals received by the two cars of an operator is dependent on the movement of the target or object, whereas the phase displacement between the signals applied to the two ears is dependent on the position of the antenna array with respect to the target or object.

I claim as my invention:

1. In apparatus for locating the position of an object which moves with respect to a place of observation, the combination of means for generating high frequency waves, means for directing a portion of said waves toward said object, means for gathering the waves reflected from said object at a plurality of points near said place of observation and mixing the same with a directly-received portion of said high frequency waves to produce beats at each of said gathering points, means for detecting said beats and feeding the same to the ears of an operator to excite the binaural sense of the operator, whereby the operator is informed of the position of said object with reference to said place of observation.

2. In apparatus for locating the position of an object which moves with respect to a place of observation, the combination of means for generating high frequency waves, means for directing a portion of said waves toward said object, 55 means at at least two points at equal distances on opposite sides of said wave-directing means for gathering waves reflected from said object and mixing the same with a directly-received por-,

tion of said high frequency waves to produce so beats at said gathering points, said wave-directing means and gathering means being adapted to be moved in unison to scan the area which is believed to include said object, means for detecting and amplifying said beats and feeding the same to the ears of an operator to excite the binaural sense of the operator to inform the operator of the position of said object with reference to said place of observation.

3. In apparatus for locating the position of an object which moves with respect to a place of observation, the combination of means for generating high frequency waves, means for directing 'a portion of said waves toward said object,,means for gathering and mixing a portion of the waves reflected from said object with a directly-received portion of said high frequency waves at two points at equal distances" on opposite sidesof said wave-directing means to produce a beat at each of said points, means for detecting said beats and feeding the same to the ears of an operator to excite the binaural sense of the operator whereby the operator is informed of the position of said object in azimuth with respect to said wavedirecting means, other means for gathering and mixing a portion of the waves reflected from said object with a portion of-said direct waves at two-points at equal distances on two other opposi'te sides of said wave-directing means to produce a beat at each of said points, means for detecting said beats and feeding the sameto the ears of another operator to excite the binaural senseof the operator whereby the operator isinformed "as'to the position of said object in elevation with respect to said wave-directing means. 4. The method of'locating the position of an object which moves with respect to a place of observation, consisting in producing a high frequency waves at the place of observation, directing said high frequency waves toward said object, gathering the waves reflected from said object at a plurality of points near saidplace-of observation and mixing the same with a directly-received portion of said high'frequency waves, utilizing the frequency difference between said directly-received high-frequency waves and said reflected waves which is caused by the movement of said object to produce a beat at each of said gathering points, detecting said beats and feeding ."the same to the ears of an operator to excite points at equal distances on opposite sides of said wave-directing reflector for gathering a portion of the waves reflected from said object and mixing the same with directly-received portions of the high-frequency waves to produce a beat at each of said gathering points, a second pair of reflectors located at equal distances on two other opposite sides of said wave-directing reflector for gathering other portions of the waves reflected from said object and mixing them with directly-received portions of said high frequency Waves to produce other beats at each of said second gathering points, said wave-gathering reflectors being located in the same plane and disposed equal distance and equal angularly about a centerline perpendicular to the plane, said wavedirecting reflector being located on said centerline and forwardly of said plane, microphones in *said wave-gathering reflectors for detectin said beats, amplifier means, means connecting said microphones to said amplifier-means, and means for feeding the output from said amplifier means to the ears of operators to excite the binaural sense of the operators to inform them of the position of said object in azimuth and elevation with respect to said place of observation.

6. In apparatus for locating the position of an object which moves with respect to a place of observation, the combination of means for generating high-frequency radio waves, means for directing said waves toward said object in a narrow beam, means located at equal distances on two opposite sides of said wave-directing means for gathering waves reflected from said object, means for generating and mixing local oscillations of said high-frequency with said reflected waves to cause beats, and means for detecting said beats and feeding the same to the ears of an operator to excite the binaural sense of the operator to inform him of the position of said object with reference to said place of observation. v

7.'In apparatus for locating the position-of an object which moves with respect to a place of observation, the combination of means for generating high-frequency radio waves, means for directing said waves toward said object in a narrow-beam, means located at equal distances on at least two opposite sides of said directing means for gathering waves reflected from said object, said wave-directing and gathering means being adapted to be moved in unison to scan theare'a including the object, means for generating local oscillations of said high frequency for mixing with the reflected waves gathered at each of said points to cause beats, means for detecting said beats, a radio receiver, means connecting said detecting means to said receiver, said receiver including means creating oscillations for further mixing with said first beats to produce second beats and means for amplifying said second beats, and means for feeding the output from said receivers to the ears of an operator to excite the bin-aural sense of the operator to inform him of the position of said object with reference to said place of observation.

3. In apparatus for locating the position of an object which moves with respect to a place of observation, the combination of means for generating high frequency radio waves, means for directing said waves toward said object in a narrow beam, means located on two opposite sides of said wave-directing means and at equal distances therefrom for gathering waves reflected from said object, separate means for generating oscillations of said high-frequency for mixing with said reflected waves to produce a beatat each of said gathering points, means for detecting each of said beats, radio receivers, means for connecting each of said detectin means to one of said receivers, each of said receivers including means for mixing said beats with other oscillations to produce a second beat and means for amplifying said second beats, and means for feeding the output from said radio receivers to the ears of anroperator to excite the binaural sense of the operator to inform him of the position of said object with reference to said .place of observation.

9. In apparatus for locating the position of an object which moves with respect to a place of observation, the combination of means for generating high-frequency waves, means for directing said waves towards said object, means at a plurality of points at equal distances on opposite sides of said wave-directing means for receiving waves reflected from said object,, said wave-directing and gathering means being movable in unison for scanning the area including the object, means for generating and mixing oscillations of said high frequency with the reflected waves gathered at each of said points to produce a first beat at each of said gathering points, means for detecting said beats, means for generating and mixing other oscillations with said first beats to produce second beats, and means for feeding said second beats to the cars of an operator to excite the binaural sense of the operator to inform him of the position of said ob ject with reference to said place of observation.

10. In apparatus for locating the position of an object with respect to a place of observation, the combination of means for generating'high frequency waves, an antenna system for directingsaid waves towards said object and gathering, the waves reflected from said object, said antenna system having a polar beam for at least one of the transmitted and reflected waves which is of less width in azimuth than in elevation, means for moving said antenna system between positions displaced angularly about a line extending in the direction of said polar beam, means for detecting the signal created by said reflected waves, and means for rendering said signal audible to an operator to inform the operator of the .position of said object with reference to said place of observation.

11. In apparatus for locating the position of an object with respect to a place of observation, the combination of means for generating high frequency waves, an antenna system for directing .said waves toward said object and gathering the .waves reflected from said object, means for detecting the signal created by said reflected waves, means for rendering said signal audible to an operator .to inform him of the position of said object with reference to said place of observation, said antenna system having a polar beam comparatively wide in azimuth when said antenna system is in one position which is utilized for approximately locating objects, said antenna system being adapted to be rotated from this position to another position in which latter position said polar beam is narrower in azimuth which enables said object to be very accurately located in azimuth.

12. In apparatus for locating the position of an object with respect to a place of observation, the combination of means for generating high frequency waves, an antenna system, said antenna system comprising a first row of parabolic reflectors for directing said waves toward said object and a second row of parabolic reflectors,

parallel to said first row, for gathering the waves reflected from said object, said antenna system having a polar beam comparatively wide in azimuth when said rows of reflectors are in substantially vertical position, in which position said system is utilized for approximately locating ob- .jects, said system being adapted to be rotated from this position to a second position wherein the rows of reflectors are substantially horizontal, in which second position the polar beam of said system is substantially narrower in azimuth than when in said first position, which enables said object to be accurately located in azimuth, means for detecting the signal created by' said reflected waves, and means for rendering said signal audible to an operator to inform him of the position of said object with reference to said place of observation.

13. In apparatus for locating an object which moves with respect to a, predetermined station,

means for producing at said station an alternating quantity having a predetermined frequency, said quantity comprising an alternating primary radiation of said predetermined frequency capable of reflection from said object, said radiation when incident on said object producing a reflected radiation having a frequency which differs from said predetermined frequency by an amount dependent on the rate of movement of the object in th line of travel of the incident radiation, means responsive to the beat frequency derived from the combination of said reflected radiation at a first point and said quantity for supplying an audible signal to a first ear of an operator, and means responsive to the beat frequency derived from the combination of said reflected radiation at a second point spaced from the first point and said quantity for supplying an audible signal to a second ear of an operator to excite the binaural sense of the operator, whereby the operator is informed of the presence of the object.

14. In apparatus for locating an object which moves with respect to a predetermined observation station, means at said station for generating an alternating primary radiation of predetermined frequency capable of reflection from said object, said means including means for directing said radiation in the form of a concentrated beam in a desired direction, a pair of radiation receivers located at equal distances on opposite sides of said radiation directing means for receiving radiation reflected by said object when the object is in the path of said beam, said reflelted radiation having a frequency which differs from said predetermined frequency by an amount dependent on the rate of movement of said object along the line of travel of said beam, said radiation receivers being positioned to receive radiation directly from said first-named means, separate means associated with each of said radiation receivers for producing an audible signal dependent on the beat frequency obtained by heterodyning said reflected radiation with radiation received directly from said first-named means, said audible-signal-producing-means including means for supplying the audible signals to .the ears of an operator to excite the binaural sense of the operator whereby the operator is informed of the presence of said object.

LEWIS W. CHUBB.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 1,889,614 Rice Nov. 29, 1932 1,973,673 Rice Sept. 11, 1934 2,018,463 Muchow Oct, 22, 1935 1,471,547 Chilowsky et al Oct. 23, 1923 1,562,950 Fessenden Nov. 24, 1925 1,864,638 Chilowsky June 28, 1932 2,223,224 Newhouse Nov. 26, 1940 Disclaimer 2,416,155.-Lewis W. Ohubb, Pittsburgh,- Pa.

Feb. 18, 1947. Disclaimer filed May house Electric Corporation.

Hereby enters this disclaimer to .cla

[Ofiic'ial Gazette, Sept. 5, 1950.]

POSITIQN LOCATOR. Patent dated 27 l950, byQthe assignee, Westingims 1, 4, and 13 of said jaatent.

Disclaimer 2,416,155.Lewis.; W. Ohubb, Pittsburgh; Pa. POSITIQN LOl-QQ' DR.

Feb. 18, 1947. Disclaimer filed May 27 195'Q,; 51 *th house Electric Oarpoiation. 1 Hereb enters this disclaimer to Claims 1, 4, and 130i s'ai pa tent. v ficialG'azefte, Sept. 5, 1950.]

I ee, Westmg it figment da ted 

